Knitting machines and methods



Sept. 19, 3967 R. w. SHANNON 3,342,043

KNITTING MACHINES AND METHODS Filed Dec. 27, 1963 6 Sheets- Sheet l F I L INVENTOR: RALP w. SHANNON BY /Z i 4 NEYS ATTO p 19, 1967 R. w. SHANNON KNITTING MACHINES AND METHODS 6 Sheets-Sheet 2 Filed Dec. 27, 1963 INVENTOR. RALPH W. SHANNON f ATTORNEYS p 19, 1967 R. w. SHANNON KNITTING MACHINES AND METHODS 6 SheetsSheet 3 Filed Dec. 27, 1963 FIG. 3.

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INVENTOR. RALPH W. SHANNON ATTORNE S Sept. 19, 1967 R. w. SHANNON 3,342,043

KNITTING MACHINES AND METHODS Filed Dec. 27, 1963 6 Sheets-Sheet 6 M INVENTOR.

RALPH W. SHANNON ATTORNEYS United States Patent 3,342,043 KNITTING MACHINES AND METHODS Ralph W. Shannon, Lalreport, N.I I., assignor to Scott & Williams, Incorporated, Laconia, N.H., a corporation of Massachusetts Filed Dec. 27, 1963, Ser. No. 333,860 11 Claims. (Cl. 66111) This invention relates to knitting machines and methods and has particular reference to double or superposed cylinder machines and the operations thereof for the production of Separate stockings, the knitting of each stocking being intiated on bare needles.

Superposed cylinder machines have been widely used for the production of broad ribbed and links-links hosiery. However, hosiery blanks have been produced in the form of continuous string work which is tensioned away from the stitch forming point by the use of equeeze roll takeups. In this operation the stockings have been initially tied together by a draw thread which is later removed to separate the blanks. A typical machine of this type is illustrated in Bristow Patent 2,763,144. The reason for the confining of operation of such machine to the production of string work is that, as is well known, because of the close approach of the cylinders to each other and the existence, at times, of a cage of needles bridging the cylinders to effect needle transfers, the yarn feeding and clamping and cutting devices have necessarily been confined to the region outside the cylinders. This makes difficult the certainty of proper makeup in starting individual stockings on bare needles.

The general object of the present invention is the production of separate stocking blanks which as each blank is completed are pressed off the needles, the next blank being started on bare needles. The production of individual blanks eliminates the need for manual removal of the draw thread for separation.

The usual squeeze roll take-up arrangement is also eliminated. A further object of the invention has to do with the production of proper tension on the fabric when individual stocking blanks are produced.

These and further objects of the invention will become apparent from the following description, read in conjunction with the accompanying drawings, in which:

FIGURE 1 is a vertical section through the portions of a superposed cylinder machine which are pertinent to the present invention, the remaining parts of the machine being conventional;

FIGURE 2 is a similar section enlarged to show better the details of construction;

FIGURE 2A is an elevation of a sinker shown separately to clarify its structure;

FIGURE 3 is a horizontal section taken on the plane indicated at 3-3 in FIGURE 1;

FIGURE 4 is an inside development of the cams which operate on the usual sliders of a knitting machine of this yp FIGURE 5 is a diagram illustrating the butt arrange ment on the sliders, there being indicated at the right of this figure the assembly of upper and lower sliders and the double ended needles associated therewith;

FIGURE 6 is a perspective and partially sectioned view illustrating the operation of the takeup provided in accordance with the invention;

FIGURE 7 is a perspective view showing the introduction of yarn for makeup by use of a special finger; and

FIGURE 8 is a fabric diagram showing a typical makeup provided in accordance with the invention.

As will be readily recognized by those skilled in the art, the machine described hereafter is largely conventional and involves operations which, except for those 3342,43 Patented Sept. 19, 196'? directly involved in the invention, as in makeup, are carried out in usual fashion. Thme are not changed by the invention which does not interfere at all therewith. Accordingly, there will be described only such changes in this type of machine and in its operation as are directly concerned with the invention.

As is well known, superposed cylinder machines are of two general types: the simpler type is used to produce broad ribs together with 1 x 1 or similar narrow rib arrangement with omission of ribs in heel and toe formation, while the more elaborate type involves provision for selective transfer of needles between the cylinders under pattern control to produce links-links work. For simplicity of description of the invention, there will be described the first type of machine; but it will be immediately apparent that the invention is equally applicable to links-links machines without any conflict with the normal design-producing selective operations.

Referring first to FIGURES 1 and 2, the machine comprises the lower cylinder 2 and the upper cylinder 4 driven to rotate and reciprocate in unison, these cylinders being longitudinally slotted for the reception of the usual lower and upper sliders 5 and 8. These sliders control and effect transfer from one cylinder to the other of needles 10 having the upper hooks 12 and lower hooks 14 associated with the usual pivoted latches. The lower sliders are provided with knitting butts 16 and transfer butts 18, while the upper sliders are provided with knitting butts 20 and transfer butts 22. Upper sliders of one group also are provided with special butts 24 referred to in more detail hereafter.

Sinkers 26 (FIGURE 2A) which are generally conventional in construction and operation are mounted as usual to extend between the needles and oscillate in their movements. They comprise the usual curved body portions 28, operating butts 30 and nebs 32. The sinkers differ from those which are conventional only in the provision of notches 34 exterior to the nebs 32. In the prior art the outer ends of the sinkers have generally been merely continuations of the upper edges of the nebs. In accordance with the present invention the notches 34 are used to retain loops properly as will be brought out hereafter.

Reference may now be made to FIGURE 4 showing the cams which act upon the butts of the sliders.

As usual, at center cam 36 is flanked by the forward and reverse stitch cams 38 and 40 which effect stitch drawing movements of needles in the lower cylinder. The usual raising pickers 42 and 44 are provided, there being also provided the usual lowering picker 46. The stitch cam 38 lowers needles which have taken yarn at the main feed to the level established by a landing cam 48, and the needles are then raised by cam 50 which has'a rise 52, a dwell 54, and then a further rise 56 arranged to raise the needles to clearing level. At the auxiliary feed the needles are lowered successively by cams 58 and 60 to the landing cam 62, and then rise to -a clear level is effected by the successive cams 66, 68, 70 and 72. A cam 74 is also arranged to act on the knitting butts of the lower sliders, but its purpose is to lift lower butts to a level to be engaged by cam 76 for transfer to the upper cylinder. Transfers occur in conventional fashion involving the usual dividing cam 78 and the lowering cam 80 which acts on the transfer butts 22 of the upper sliders.

Arranged to act on the lower knitting butts of the upper sliders are the earns 82, 84 and 86 at the main fee-d, the last cam constituting the upper stitch cam for this feed. Associated with it is the landing cam 88 followed by the successive cams 90, 92 and 94 to effect clearing. If needles in the upper cylinder are to knit at the auxiliary feed they are raised by the successive cams 96, 98 and 100, the latter constituting the stitch cam at the auxiliary feed and being associated with a landing cam 102. Successive r? cams 104, 106 and 108 will lower needles to cleared level.

A special radially movable cam 110 is provided to act on the special slider butts 24.

It may be here noted that the so-called welt races for the upper and lower cylinders, respectively, are indicated at 112 and 114. As usual, various of the cams are radially movable for the usual purposes of transition from twofeed knitting to single feed knitting and vice versa, for effecting location of instep needles in inactive position and restoring them to active position, for effecting selective transfers between the cylinders, etc. Since these operations are conventional, reference will be made only to special operations provided in accordance with the invention.

The main feed latch guard is shown at 116. Above the usual V notch 121) in this guard, provided to permit latch movements, there is the relief groove 118 through which there is directed from a nozzle 122, for the purpose of closing latches of needles in the upper cylinder, a blast of air directly against the latches to throw them downwardly to their closed positions.

The latch guard at the auxiliary feed is shown at 124. Preceding this, and above the dwell 54 of the cam 50 there is the latch opener 126 for the needles operating in the lower cylinder. The latch opener for needles operating in the upper cylinder is shown at 128. It will be understood that as the cylinders rotate the needles will move in the direction of the arrow from right to left through the nonrotatable cams just described.

Reference may be next made to FIGURE which diagrarns the disposition of the various slider butts. Starting with the knitting butts 16 of the lower sliders 6, it will be seen that the butts are divided into four groups: those having long butts indicated at 16a, those having intermediate butts indicated at 16b, those having short butts indicated at 16c, and another group having intermediate butts 16a.

The transfer butts 18 of the lower slider are of two types which alternate throughout the entire circle, the butts being long as indicated at 18a and short as indicated at 18b.

Knitting butts 20 of the upper sliders fall in two groups: long butts 20a and short butts 20b. The latter form a panel indicated as 130 for convenience of further reference.

The transfer butts 22 of the upper sliders fall in three groups, long butts 22a, short butts 22b and intermediate butts 220. As illustrated, the long butts 22a are arranged in pairs alternating with pairs of other butts. These other butts in the portion of the circle corresponding to long knitting butts of the lower slider are short butts 2212, while in the remaining portions of the circle they are the intermediate butts 220. The arrangement illustrated is for the formation of 2 X 2 broad rib fabric; if other rib formations are to be produced, the sequences of the 'butts are correspondingly arranged, for example in 3x6 repeats. or the like.

The butts 24 are associated with alternate sliders in the panel indicated at 130. Their alignment with the other butts mentioned is indicated by the vertical lines 132 and 134. During rotation the butts rotate through the cams in the direction indicated by the arrow 136, the butt arrangement being shown looking outwardly from the axis of rotation.

Referring to FIGURE 3, the main feed yarn fingers are indicated at 138 and are conventional both with respect to form and their operating and controlling elements. For carrying out the present invention there is an additional yarn feeding finger 140 at the main feed which is separately controlled in a fashion which is conventional in itself and corresponds to that illustrated and described in Bristow Patent 2,470,803, FIGURE 3, wherein a similar finger is provided for plating. Control is effected as shown in said patent by cams on the usual main cam drum of the machine.

One or more auxiliary yarn feeding fingers such as 4 142 are provided in conventional fashion at the auxiliary feed.

The latch opener 126 for needles operating in the lower cylinder is mounted in a block 144 pivoted on a shoulder screw 146 and is urged toward the needles by a spring 148. A Bowden wire 150 having a sheath 152 as connected to the block 144 at 154 and is arranged to be acted upon by cams on the main cam drum of the machine to withdraw the latch opener against the action of spring 148.

The latch opener 128 for needles operating in the upper cylinder is mounted in a pivoted block 156. It is operated in conventional fashion by the two feed mechanism shown in Oberholtzer Patent 2,557,137, FIGURES 3 and 4. A needle presser 158 is adjustably mounted in a block 160 carried by the latch opener 128.

Yarn trapper 139 is representative of the nest of trappers conventionally used to clamp and cut yarns associated with yarn fingers 138. A similar yarn trapper is shown at 141 for the yarn fed by finger 140.

Mounted for axial movement by a sleeve 164 is a rod 162 extending downwardly through the upper cylinder and carrying at its upper end a weight 166 which may be pushed upwardly through a spring 168 by the action of a lever 172 on the plate 170 of a loose collar surrounding the rod. The lever 172 is arranged to be acted upon at suitable times by cams on the main cam drum through intermediate linkages. At its lower end the rod 162 carries a head 174 slotted to provide guides and sockets for fingers 176, for example, six in number, the lower ends of which are circumferentially extended as indicated at 178 to engage fabric entering the sinker pot 180 during knitting.

The bore of cam block 175 is engaged by the outer vertical edges of fingers 176 to maintain the extended position 178 when inactive as shown in FIGURE 1. When the tension mechanism is released to engage the fabric the extended position 178 is maintained by cam block 175 until the fabric is contacted by the lower outer ends of fingers 176. In this position the radii on the upper edges of fingers 176 are located at the lower edge of the bore in carn block 175, as shown in FIGURE 2.

Rod 162 is provided with a longitudinal groove 163 that is slidably engaged with the pilot end of screw 165. By this means, the tension mechanism is rotatable with the needle cylinders.

Fingers 176 are retained in head 174 by spring band 182 and are arranged to yield radially when acting on the fabric. Except when under control of cam block 175 and when engaged in the fabric, the fingers 176 yield inwardly so that upon elevation of the tension mechanism after disengagement from the fabric, the lower outer ends more or less collapse inward to afford withdrawal through the interior of a portion of the knitted tube. When acting on the initial portion of a stocking they engage it lightly under centrifugal action, the lower ends of the fingers below spring 182 being more extended and heavier than the portions above this spring.

The action on the fabric is particularly illustrated in FIGURE 6.

The operation is as follows:

Consideration may be most conveniently first given to a preferred procedure for the completion of a stocking. After conventional completion of a toe pocket by reciprocatory single feed knitting with all needles in the lower cylinder, rotary knitting is resumed and a few plain courses are knit single feed by needles in the lower cylinder to provide the loopers waste. Preparatory to pressoff an anti-runback welt is formed. It will be understood that cam movements as will now be described are effected in conventional fashion by steps of the main cam drum.

Before production of the anti-runback welt, and after the formation of the plain loopers waste courses -a few courses of 1 x 1 rib knitting are produced with the stepping of cam 74 part-way in as short knitting butts 16c pass it. Simultaneously cam 76 is moved inwardly far enough to raise the longer transfer butts 18a of the sliders beginning with the group having butts 16b raised by cam 74, to bring butts 18a to position for engagement with cam 76 to effect transfer of alternate needles to the upper cylinder sliders which are then raised by cam 82. In the same cam-controlling step of the main cam drum, cam 92 is stepped part-way out during passage of the long knitting butts 20a. Single feed 1 X l rib knitting then begins on the first needle in the lower cylinder associated with a knitting butt 16b.

The next operation involves the movement of cam 74 inwardly to its innermost position during the passage of the high knitting butts 16a. Cam 92 is moved all the way out as the panel of knitting butts 20b pass its position. The result of the foregoing is that upper cylinder sliders and associated needles beginning with the first part of the group 20a continue in the welt path and are not cleared by cam 94.

l x 1 rib knitting continues at the main feed. The needles in the lower cylinder are cleared in conventional fashion over the slopes 52 and 56 of cam 50, and needles in the upper cylinder are cleared by cams 106 and 108.

After transfer of needles for 1 x l rib knitting is completed cams 74 and 76 are moved out preliminary to formation of the anti-runback welt, and cam 106 is stepped part-way out as long knitting butts 20a are passing it so as not to engage butts 20b. Next, cam 106 moves fully out as the short knitting butts 20b pass it. Accordingly, rib needles, beginning with the first knitting butt in panel 130 are no longer cleared by the cams 106 and 108, but pass at welt level 112 through the main feed holding their loops and not taking yarn at this feed.

While other formations may be used, there may thus be completed two courses of 1 x l rib knitting and at least one course of welt knitting.

Cam 106 is then moved part-way inwardly as the short butts 20b are passing its position. Then this cam is moved all the way in as long butts 20a pass it. This action effects clearing of rib needles by cam 108. Rib knitting is thus resumed.

Preliminary to press off the latch opener 128 and needle presser 158 are moved to active position. At this time the main feed yarn finger is withdrawn. Latch opener 126 is also moved into active position.

Press-off is effected as needles in the upper and lower cylinder are drawn by the action of the main feed stitch cams 38 and 86.

As a result of the foregoing, a completed stocking blank is dropped off the needles, the blank to be completed to form a stocking by the conventional looping operation.

It may be noted that the sequence of operations just described is similar to that involved in Bristow Patent 2,763,144 with the exception that in that patent press-off of a stocking blank is not affected.

The makeup on bare needles for the starting of the next stocking involves control by the main cam drum of a number of operations. The needle cylinders rotate continuously through press-01f and makeup.

Prior to make-up, latch opener 126 opens lower cylinder needle latches. They are prevented from closing by latch guard 124. As movement continues, the associated upper cylinder sliders 8 are lowered by cam 108 and the extremities 9 of these sliders prevent latch closure. When these sliders are elevated by cam 82, latch guard 116 then maintains the open latch condition until the needles reach the latch turn-over point at V-opening 120.

The upper cylinder needle latches are opened by 128 as their sliders are lowered by cam 106. The extremities 7 of lower cylinder sliders 6 prevent closure of the latches of upper cylinder needles until these needles are raised by cam 82 when latch guard 116 maintains the open latch condition until V-opening 120 is reached. Cam 106 is partially withdrawn to miss butts 20b during the last cylinder rotation as the latches are being opened.

Since the needles are divided 1 x 1 from the previous operation prior to press-01f, no needle transfer action takes place at the transfer station.

Special yarn finger 140 is introduced a few needles ahead of the first needle associated with a butt 16b during the initial part of the makeup revolution, during which cam 106 is fully withdrawn during the passage of needle panel 130 and cam 110 serves then to lower the needles associated with sliders having butts 24. The last needle of this group is the last to be lowered and have its latch opened by 128. Opening of a conventional valve controlled by the main cam drum introduces air under pressure through the tube 122 to close by jet impingement upper cylinder needle latches at the V-opening 120. All needles take yarn at the main feed as they are drawn by cams 38 and 86, respectively, beginning with the first needles associated with butts 16b and 20a. Closure of latches of the needles in the upper cylinder by the action of the air insures positive entry and retention of the introduced yarn in the needle hooks, the closure taking place immediately after the presentation of the yarn to their hooks.

Lower cylinder needles are cleared over cam 50, so that the main yarn laid in their hooks becomes located on their shanks below the open latches. Upper cylinder needles remain at welt level 112 after rise thereto since cam 92 is withdrawn, its position being the result of'the operation previously described preceding press-off. During this initial cylinder revolution for make-up the aux iliary feed yarn is introduced by conventional operation of the two-feed mechanism to activate bolt cam 58 and finger 142. Lower cylinder needles take the auxiliary feed yarn, draw loops L (FIGURE 8) and are cleared over cam 70. Upper cylinder needles at welt level 112 do not take the auxiliary feed yarn but hold the main yarn loops L In the next passage by the main feed, the lower cylinder needles again take the main yarn to draw stitches L Since cams 106 and 110 are Withdrawn the upper cylinder needles continue in the welt path and therefore do not take the main feed yarn. Cam 92 is then moved in, part way as butts 2% pass it so that it engages butts 20a, and then fully in, and the upper cylinder needles will be cleared and will take the yarn at the auxiliary feed to produce stitches L The lower cylinder needles also take the auxiliary yarn to produce the stitches L As will be evident from FIGURE 8 this produces the 1 x 1 course of auxiliary yarn indicated at C Alternatives to the operation just described may be provided. For example, if it is desired to hold the loops L in the upper cylinder needles, the clearing may be delayed by delaying the introductions of the cams 92, 106 and 110.

Following the make-up, yarns are taken at both feeds and at least one cylinder revolution is completed, the air blast at 122 is terminated, and the latch openers 126 and 128 and needle presser 158 are withdrawn. At the end of the first cylinder revolution a rubber finger may optionally be introduced at the main feed if an inlaid rubber top is desired. The inlaying of rubber in this fashion is conventional.

The two feed 1 x l rib top knitting may be continued for as many courses as desired. Alternatively, cams 74, 76 and may be introduced during these next courses to effect 2 -x 2 broad rib knitting after the makeup, or this may occur earlier so that only one 1 x 1 course such as C is produced. If rubber has been introduced the rubber finger will be withdrawn after the desired number of courses are produced in the top with this inlaid elastic yarn.

A typical welt made by the described operation is shown in FIGURE 8. In this figure the main feed yarn M is shown plain and the auxiliary feed yarn A is shown stippled 1 X 1 knitting continues through course C as shown this being the sole normal 1 x 1 course, though these 1 x 1 courses may be continued as long as desired,

7 transition then being made, for example, to 2 x 2 rib knitting.

It is during the makeup, welt and initial courses of rib knitting that the special sinkers 26 having the notches 34 are highly desirable for loop control since they will hold the loops upwardly as clearing occurs and will prevent the yarn from getting below the ends of the sinkers.

The importance of special yarn finger 140 can best be appreciated by comparison with the normal operation of conventional yarn fingers 138. When conventional yarn changes occur, these fingers are operated to extend the introduced yarns from trappers 239, of which one is shown in FIGURE 3, to the needles in the direction of cylinder rotation. Under these conditions the taking of yarn by needles is dependent upon the previous loop on the needle which causes the latch to turn over and sweep the introduced yarn into the hook as the needle is being drawn. Y

Since, in this instance, introduction of yarn to bare needles is essential to makeup, special finger 140 is controlled separately and operated to extend the introduced yarn from trapper 141 in a direction opposing cylinder rotation toward the approaching needles. By this action the yarn is presented tangentially to the circle of the needle hooks and insures positive engagement of the yarn in them, this action being further insured by the closing of the latches of the needles in the upper cylinder by the air jet at 122.

Trapper 141 is positioned close to the needle circle and just beyond the sinker knockover point for the main feed. Therefore the introduced yarn is laid across the throats of the withdrawn sinkers and as rotation continues, the inward movements of the sinkers at knockover tend to contribute further to the positive positioning of the introduced yarn well into the hooks of the needles. The action of pin 143 following cam 145 under the action of spring 147 locates the end of feeding finger 146 at the end of its movement well inwardly towards the cylinder to locate the line of aproach of the yarn against the needles.

Conventional makeup and welt knitting are generally accomplished single feed, whereas it will be noted from the foregoing that two feeds are employed in these operations. This is advantageous in that the ordinary sinker cam-ming for two feed knitting may be used. In this camming, involving fixed elements, the sinkers are withdrawn at the auxiliary feed whether or not that feed is in action. If single feed makeup on bare needles was used, Withdrawal of sinkers would have to be prevented at the auxiliany feed which would involve complications of structure and operation. When the auxiliary feed is brought into operation during the first cylinder revolution of makeup, stitches are immediately drawn and the sinker withdrawal is permissible.

Although mechanical latch openers are shown and described, it will be evident that air blasts may be used for opening latches in the fashion set forth in Shelrnire Patent 2,658,366.

Following the knitting of the initial courses to achieve a sufiicient length of fabric to extend inwardly within the range of the fingers 176 having the ends 178, the spindle 162 is released by the lever 172 controlled by the main cam drum so that the fingers may engage and tension the fabric during the knitting of the leg as shown in FIG- URE 2.

The leg is knit conventionally two-feed with the machine illustrated, and before the start of the heel the takeup assembly is elevated to inactive position by the action of lever 172 and remains in this position during the reciprocatory knitting of the heel. The heel is knitted single feed, though, of course, it may be knit two-feed with conventional changes of mechanism.

After the heel is completed, the takeup assembly is released by the lever 172 and the fingers will then engage the fabric in the heel pocket for tensioning during the 8 knitting of the foot, this engagement being illustrated in FIGURE 6.

Before the knitting of the toe pocket begins the takeup is again rendered inactive by being lifted by the lever 172, and the toe knitting proceeds in conventional fashion, either single feed or two feed, by reciprocatory knitting. With the completion of the toe pocket the operations are as already described. The takeup assembly is released after completion of the toe pocket and engagement in the pocket exists in completing of the stocking to imparting tension during press-off.

When the press off occurs and the stocking is free of the needles, the :fingers 176 readily yield inwardly as the assembly is elevated by lever 172 to inactive position as the stocking is dropped. Since engagement of these fingers was in the toe pocket, they are required to withdraw through only a relatively short portion of the completed stocking, the weight of the stocking being sufiicient to permit it to drop off.

It will be evident that various changes in details may be made without departing from the invention which is accordingly not to be considered as limited except as required by the following claims.

What is claimed is:

1. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders slidably mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for controlling movements of said sliders, means for feeding yarn to needles in both the upper and lower cylinders, and means for closing latches of bare needles to trap yarn fed by said feeding means to the hooks of such needles.

2. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders slidably mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for controlling movements of said sliders, means for feeding yarn to needles in both the upper and lower cylinders, and means for closing latches of bare needles to trap yarn fed by said feeding means to the hooks of such needles, the last mentioned means comprising means providing a jet of air directed against the latches to move them to closed position.

3. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders slidably mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for controlling movements of said sliders, means for feeding yarn to needles in both the upper and lower cylinders, means effecting opening of latches of bare needles so that yarn may be fed to the hooks thereof, and means for closing latches of bare needles to trap yarn fed by said feeding means to the books of such needles.

4. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders slidably mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for controlling movements of said sliders, means for feeding yarn to needles in both the upper and lower cylinders, means effecting opening of latches of bare needles so that yarn may be fed to the hooks thereof, and means for closing latches of bare needles to trap yarn fed by said feeding means to the hooks of such needles, the last mentioned means comprising means providing a jet of air directed against the latches to move them to closed position.

5. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders slidably mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for controlling movements of said sliders including means distributing needles in alternating fashion in said cylinders, means for feeding yarn to needles in both the upper and lower cylinders, and means for closing latches of bare needles in one of said cylinders when the needles are distributed in said alternating fashion to trap yarn fed by said feeding means to the hooks of such needles.

6. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders slidably mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for controlling movements of said sliders, including means distributing needles in alternating fashion in said cylinders, means for feeding yarn to needles in both the upper and lower cylinders, and means for closing latches of bare needles in one of said cylinders when the needles are distributed in said alternating fashion to trap yarn fed by said feeding means to the hooks of such needles, the last mentioned means comprising means providing a jet of air directed against the latches to move them to closed position.

7. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders slidably mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for controlling movements of said sliders, means for feeding yarns at a plurality of feeding stations to needles in both the upper and lower cylinders, and means for closing latches of bare needles in one of said cylinders to trap yarn fed by said feeding means at one of said feeding stations to the hooks of such needles.

8. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for feeding yarns to needles in both the upper and lower cylinders at a plurality of feeding stations, means for closing latches of bare needles in one of said cylinders to trap yarn fed at one of said feeding stations to the hooks of such needles, and means controlling said sliders, yarn feeding means and latch closing means to effect, sequentially, location of needles in alternating fashion in said respective cylinders, location of a yarn at one feeding station in the hooks of bare needles in both of said cylinders and clo sure of latches of needles in one of said cylinders to trap said yarn, seizure of yarn at a second feeding station by needles in only one of said cylinders, and thereafter seizure of yarn at the first feeding station only by those needles which seized yarn at the second feeding station.

9. A circular knitting machine comprising upper and lower superposed needle cylinders, sliders mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for feeding yarns to needles in both the upper and lower cylinders at a plurality of feeding stations, means for closing latches of bare needles in one of said cylinders to trap yarn fed at one of said feeding stations to the hooks of such needles, and means controlling said sliders, yarn feeding means and latch closing means to efi ect, sequentially, location of needles in alternating fashion in said respective cylinders, location of a yarn at one feeding station in the hooks of bare needles in both of said cylinders and closure of latches of needles in one of said cylinders to trap said yarn, and seizure of yarn at a second feeding station by needles in only one of said cylinders.

10. The method of effecting makeup on a circular knitting machine comprising upper and lower superposed needle cylinders, sliders mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for feeding yarns to needles in both the upper and lower cylinders at a plurality of feeding stations, means for closing latche of bare needles in one of said cylinders to trap yarn fed at one of said feeding stations to the hooks of such needles, and means controlling said sliders, yarn feeding means and latch closing means, said method comprising effecting sequentially location of needles in alternating fashion in said respective cylinders, location of a yarn at one feeding station in the hooks of bare needles in both of said cylinders and closure of latches of needles in one of said cylinders to trap said yarn, seizure of yarn at a second feeding station by needles in only one of said cylinders, and thereafter seizure of yarn at the first feeding station only by those needles which seized yarn at the second feeding station.

11. The method of effecting makeup on a circular knitting machine comprising upper and lower superposed needle cylinders, sliders mounted in said cylinders, latch needles mounted to slide in said cylinders and controlled by said sliders, means for feeding yarns to needles in both the upper and lower cylinders at a plurality of feeding stations, means for closing latches of bare needles in one of said cylinders to trap yarn fed at one of said feeding stations to the hooks of such needles, and means controlling said sliders, yarn feeding means and latch closing means, said method comprising effecting sequentially location of needles in alternating fashion in said respective cylinders, location of a yarn at one feeding station in the hooks of bare needles in both of said cylinders and closure of latches of needles in one of said cylinders to trap said yarn, and seizure of yarn at a second feeding station by needles in only one of said cylinders.

References Cited UNITED STATES PATENTS 334,681 1/1886 Smalley 66-111 1,082,239 12/1913 Rosenthal 661 11 X 2,214,706 9/1940 Holmes 661 11 2,639,596 5/1953 Parham 6641 X 2,658,366 11/1953 Shelmire 66-111 2,697,338 12/ 1954 Shortland 661 11 2,971,360 1/1961 Landry 66-150 3,115,024 12/ 1963 Walrabenstein 66--111 X 3,134,250 5/1964 Manger et al. 66-172 FOREIGN PATENTS 565,704 11/ 1944 Great Britain.

MERVIN STEIN, Primary Examiner. W. C. REYNOLDS, Examiner. 

1. A CIRCULAR KNITTING MACHINE COMPRISING UPPER AND LOWER SUPERPOSED NEEDLE CYLINDERS, SLIDERS SLIDABLY MOUNTED IN SAID CYLINDERS, LATCH NEEDLES MOUNTED TO SLIDE IN SAID CYLINDERS AND CONTROLLED BY SAID SLIDERS, MEANS FOR CONTROLLING MOVEMENTS OF SAID SLIDERS, MEANS FOR FEEDING YARN TO NEEDLES IN BOTH THE UPPER AND LOWER CYLINDERS, AND MEANS FOR CLOSING LATCHES OF BARE NEEDLES TO TRAP YARN FED BY SAID FEEDING MEANS TO THE HOOKS OF SUCH NEEDLES. 